Kaori is Tsubaki's classmate, a free-spirited violinist who has been criticized by judging panels for her unwillingness to adhere strictly to the score but is popular with audiences. Kaori meets Kōsei when she asks Tsubaki to set her up with Ryōta. As their friendship grows, she eventually convinces Kōsei to play the piano again, first as her accompanist and later in a piano competition.